Steam-engine indicator



2 Sheets-Sheet 1;

(No Model.)

E. GARST. STEAM ENGINE INDICATOE.

No. 419.326. Patented Jan. 14,'1890.

A TT ORNE 78.

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2 Sheets-Sheet 2.

(No Model.)

. E. GARST.

STEAM-'ENGINE INDIGATOR.

Patented Jan. 14, 1890.

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UNITED STATES PATENT OFFICE.

EDVIN GARST, OF DAYTON, OHIO.

STEAM-ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 419,326, dated January 14, 1890.

Application filed March 20, 1889. Serial No. 303.964. (No model.)

To all whom it may concern- Be it known that I, EDWIN GARST, of Dayton, in the county of `Montgomery and State of Ohio, have invented a new and Improved Indieator, of which the following is a full, clear, and exact description.

The invention relates to steam-engine indicators forkshowing the working of the steam' in the cylinder.

The object of the invention is to provide a` .,drawings, forming a partof this specification,

in which similar letters of reference indicate eorresponding parts in all the figures.

Figure lis a side elevation of the improvement as applied, parts being in section. Fig. 2 is a plan view of the improvement. Fig. 3 is an end elevation of the same. Fig. 4 is a transverse section of part of the improvement on the line xmof Fig. 2. Fig. is an enlarged sectional side elevation of one of the cordclamps on the line y y of Fig. 6. Fig. 6 is a seotional end elevation of the same on the line z' z' of Fig. 5, and Fig. 7 is an enlarged sectional elevation of the pencil-holder.

The improved engine-indicator A is provided with a base-plate B, containing the cylinders C and D, placed parallel with each other and open at their upper ends. The lower end of the cylinder O is connected by suitable means with the interior of the steamchest E, and the lower end ofthe cylinder D is connected by like means with the interior of the cylinder F of the steam-engine G of any approved construction.

In the cylinder O is held to slide a piston H, pivotally connected with the pitman I, pivotally connected at its upper end, by the pin I', With a balancing-bearn J, provided with a curved top edge J adapted to roll on the under side of a plate K, extending parallel with the base-plate B, and supported from the same by suitable standards K'; The pivotpin I projects into a segmental slot 12, formed in a lug` 13, secured to the under side of the plate K. (See Figs. 1 and 4.) The pin I'thus forms the pivot for the pitman I, and also for the balancing-beam J to roll on the under side of the plate K. Instead of the curved top edge J which is formed in the arc of a Circle, I may form the under side of the plate K in the shape of an are of a circle and leave the top edges of the beam J straight.

In the cylinder D, connected with the steamcylinder F of the engine G, is mounted to operate a piston L, pivotally connected by the pitman L' with the balancing-beam J. On`

the latter is fornied an extension J 2, pivotally connected by a link N with the pencil-holder O, containing the pencil O', adapted to mark on1 the paper cylinder P, secured on the solid cylinder P', mounted to turn on a spindle P2, secured in the hraekets K2, fastened to one end of the plate K.-

The pencil-holder O is formed of a tube, through which passes the pencil O', and the tube O passes vthrough a Vertical slot Q', formed in a standard Q., secured to the bracket K2, and loeked in place on the cylinder P.

tube with two washers or nuts O2, fitting' against the front and rear of the standard Q. (See Fig. 7.)

On the outer end of the pencil-holder O' is secured a collar O3, provided with an annular recess engaged by the forked end of an arm R, secured to'a collar R', fastened on a transversely-extending shaft R2, mounted to slide in the standards K3, secured to the plate K. A springR3 is coiled on the said shaft R2 and presses at one end against one of the standards and at its other end against the said collar R' so as to press the latter against the other standard. The shaft R2 passes through the front standard K3, and is provided with a collar R4, located 'a short' distance f-rom the said standard, so that the in- Ward motion of the shaft R2 is limited. When the operator presses against the outer end of the shaft R2, the latter slides rearward and causes a like motion of the arm R, so that the pencil O' is pressed against the paper roll IOO P. Then the operator releases t-he pressure on the shaft R2, the spring R3 again forccs the shaft R2 to its former position,so that the arm R moves the pencil O' away from the paper cylinder P.

On the solid cylinderP', carrying the paper cylinder P, is formed a pulley P2, around which is wound twice an endless cord S, also passing` once around a pulley T, mounted to turn loosely on a stud T', secured on a plate 'l`2, hold longitudinally adj ustable on a bracket. K4, secured to a plate K. The plate T2 is made longitudinally adjustable, so as to take up any slack in the cord or rope S. On the said cord S is fastened a cross-head U, connected bysuitable means with the cross-head V of the steam-engine, so that the said steamengine cross-head imparts a forward sliding` motion to the cross-head U. thereby imparting a traveling motion to the cord or rope S. The cross-head U is preferably made of the two Sections U', (see Figs. 5 and 6,) through -which the rope passes, and each of which is provided on its outer end with a conical slotted end, threaded and adapted to receive a nut U2, which, when screwed up, forces the arms formed by the slots toward each other, and thereby securely clamps the part U' to the rope. Other suitable means may be employed instead of the cross-head U. The lefthand end of the balancing-beam J is provided with a weight JS, for counterbalancing the said beam and its connection with the pencil O'.

The operation is as follows: Then the indicator is attached to the engine G, as above described, the pressure in the steam-chest E is exerted against the piston H in the cylinder O, so that the said piston H, by its pitman I, moves the balancing-beam J into the position shown in Fig. l-that is, the curved top J' of the balancing-beam J rests against the under side of the fixed plate K, directly above the pivot-pin I'. The interior of the engine-cylinder F is connected with the cylinder D, and now as soon as the cylinder takes steam through one of its ports the piston L in the steam-cylinder D is caused to move upward, so that its pitman L' presses against the beam J, which latter thus swings upward and its curved top edge J rolls on the under side of the fixed plate K until the point of fulcrum of the balancing-beam is changed from the point c to the point b on the fixed plate K. This point Z) is half-way between the fulcrum-points of the pitmen I and L', and when the balancing-beam J has assumed this position the pressures in the engine-cylinder and the steam-chest are completely balanced. Thus it will be seen that by the upward motion of the piston L and the upward swingingmotion of the balancing-.beam J the pencil O' is raised to a certain height in front of the paper cylinder' P. The pencil O' now cannot rise any higher upon the paper cylinder until the compression in the engine-cylinder is greater than that in the steam-chest, so that the pressure on the piston L overcomes the pressure on the piston H, whereby the balancing-beam J is swung farther upward, thereby causing the pencil O' to move a short distancc higher. `When the 'port of the engine-cylinder is closed, the expansion takes place, and then the pressure in the steam-chest is greater than the pressure in the cylinder, and consequently the piston H overbalances the piston L and is moved upward as fast as the expansion takes place in the engine-cylinder F. The left-hand end of the balancing-beam J is thus caused to swing` upward and the right-hand end of the beam to swing downward, whereby the pencil draws an eXpansion-line on the paper cylinder P. Vhen the exhaust takes place, the point of fulcrum of the beam J is changed to the point c, and the pencil then rests in its lowermost positionthat is, 011 the atmosphere-line 011 the paper-cylinder P--unless a condenser is used by the engine. In that case the vacuum aets on the piston L, which causes the pencil to pass below the atmosphere-line to the extent of the vacuum. The above-described operation is then repeatcd by the next stroke of the piston in the enginecylinder F.

It will be seen that when the engine is in operation the cross-head V imparts a rotary motion to the cylinder carrying the paper cylinder P, so that the pencil O' operates in unison with the movement of the engine. It is to be understood that the pencil O' is disconnected from the paper cylinder P until the operator presses 011 the outer end of the shaft R2, so that the point of the pencil is moved inward against the paper cylinder. It is to be further understood that the pivot-pin 1' travels in the segmental slot I2 when the curved top J of the balancing-beam J rolls on the under side of the fixed plate K, as before described.

By employing` the two pistons operated from the steam chest and cylinder, respectively, I dispense entirely with the spring usually employed to counteraet the cylinderpressure and force the pencil back to the atmospheric-pressure line. These Springs must be graduated for or adj usted to different boiler-pressures, but by using cylinders C D and the balance-beam operated therefrom I can take a correct diagram from any steamengine at any Variation of the boiler-pressure without readjusting a single part.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a steam-engine indicator, the combination, with the steam chest and cylinder, of a balancing-beam, separate and independent operatin g connections between the said beam and the chest and cylinder, and a marker operated by the beam, substantially as set forth.

2. The combination, with the steam cylinder and chest and two rods or pitmen actuated, respectively, therefrom, of a balancebeam pivotally connected to said rods or pit- IOO men, a bearing-surface, on which the beam rolls orrocks between the rods or pitmen, and a marker Operated from the beam, substantially as set forth.

3. The Combination, with the steam cylinder and chest and two parallel rods Or pitmen actuated, respectively, t-herefrom, of a balance-beam pivotally connected to the outer ends of said rods or pitmen, a plate on which the beam rocks, provided with slotted lugs through which the pivot connecting the beam and one of said rods or pitmen passes, and a marker act-uated by said beam, substantially as set forth.

4. In a steam-engine indicator, the combination, with two parallel rods actuated from the steam cylinder and chest, respeotively,

of a balance-beam pivOta-lly connected to the upper ends Of said rOds or pitinen and having one end weighted, a plate On which the beam rocks, provided with slotted lugs through which the pivot connect-ing one rod Or pitman with the beam passes, and a marker operated from that end of the beam opposite to the weight, substantially as set forth.

5. In a steam-engine indicator, the combination, with a fixed plate, of a balancing-beam adapted to roll on the said fixed plate and Controlled by the steam in the steam-chest and en gine-cylinder, a pencil operated by the said balancing-beam, and a paper cylinder turned by the cross-head of the engine, and on which operates the said pencil, substan- -tially as shown and described.

6. In a steam-engine indicator, the combination, with the engine, of a balancing-beam controlled by the steam in the steam chest and cylinder of the said engine, a fixed plate on which the said balan cing-beam is adapted to roll, a pencil operated by the said balancing-beam, and a paper cylinder turned by' the said engine, and on which operates the said pencil, substantially as shown and described.

'7. In a steam-engine indicator, the combination, with two cylinders, of which one is connected with the interior of the steam-chest and the Other with the engine-cylinder, of pistons Operating in the said cylinders, and a balancing-beam Vconnected with the said pistons and adapted to opera-te a pencil, substant-ially as ,shown and described.

8. In a steam-engine indicator, the combination, with two cylinders, ofwhich one is connected with the interior of the steam-chest and the other with the engine-cylinder, of pistons Operating in the said cylinders, a balancing-beam connected with the said pistons and adapted to operate a pencil, and a fixed plate On which rolls the said balancingbeam, substantially as shown and described.

-9. In a steam-engine indicator, the combination, with two cylinders, of which one is connected with the interior of the steam-chest and the Other with the engine-cylinder, of pistons Operating in the said cylinders, a balancing-beam connected with the said pistons and adapted to operate a pencil, a fixed plate on which rolls the said balancing-beam,` and a paper cylinder turned by the engine and On which operates the said pencil, substantially as shown and described.

10. In a 'steam-engine indicator, the combination, with two cylinders, of which One is connected with the interior of the steam-chest and the Other with the engine-cylinder, of pistons Operating in the said cylinders, a balancing-beam connected with the said pistons and adapted to operate a pencil, a fixed plate on which rolls the said balancing-beam, a paper cylinder turned the engine and On which operates the s id pencil, and means, substantiallyas deser' ed, for oonnecting and disconnecting the s d pencil and the paper cylinder, as set f h. -engine indicator, the combi-* nation, with two cylinders, of which one is connected with the steam-chest and the other with the engine-cylinder, of pistons Operating in the said cylinders, a balancing-beani piv- Otally connected with'the said pistons, a fixed plate On which the said balancing-beam is pivoted and adapted to roll, and a pencil adapted to be operated by the said balancingbeam, subst-antially as shown and described. l

nation, with two cylinders, of which' one is connected with the steam-chest and the other with the engine-cylinder, of pistons Operating in. the said cylinders, a balancing-beam pivotally connected with the said pistons,a fixed plate On which the said balancing-beam is pivoted and adapted to roll, a pencil adapted to be operated by the said balancing-beam, a paper cylinder controlled by the engine and IOO IIO

on which operates the said pencil, and means,

substantially as described,for connecting and disconnecting the said pencil and the said paper cylinder, substantially as set forth.

EDW'IN GARST.

Witnesses: i

MAROUs SHOOP, MILEs S. PARsONs. 

